The present disclosure relates to an electrical switch arrangement for controlling an electrical or electronic apparatus. Additionally, the present disclosure relates to a device for controlling an electronic apparatus incorporating such a switch arrangement.
Various examples of design of a device for controlling an electronic apparatus are known that are of the type comprising a top panel, essentially planar and horizontal, on a top face of which a control member, such as the finger of a user or a stylus, can exert a control action consisting of an essentially downward-oriented pressure force, and comprising a supporting bottom reinforcement relative to which the top panel is mounted to move by an essentially downward vertical motion under the effect of the control action.
One such example of a device is, for example, described and represented in the France Patent document FR-B1-2.947.645, the content of which is hereby incorporated by reference in its entirety, in which the device includes an electrical switch, or a changeover switch, which is borne by the reinforcement and which can be actuated, under the effect of the control action, to produce a control signal for the electronic apparatus and, also, to produce a mechanical tactile sensation transmitted to the user.
The control top panel may include means for example for locating the position of the point of contact of the control action on the top face of the top panel. The top panel then constitutes a tactile “tablet”, the device possibly also including means for displaying information, notably associated with the keying operations that the user performs on the top panel.
In such a design, the electrical switch, or changeover switch, makes it possible to detect any control action consisting in exerting, on the top face of the top panel, a pressure above a predetermined so-called threshold value. Such an electrical switch with tactile effect can change state when the value of the control action becomes greater than the threshold value and, upon this change of state, the switch enables the top panel to be displaced downwards to a so-called actuation position of the switch which also produces a tactile sensation which is perceived by the user. The user is thus informed tactilely that the validation/selection action has been exerted on the control device.
According to the design proposed in the document Germany Patent Document DE-A-10.2010.026.910, the content of which is hereby incorporated by reference in its entirety, it has already been proposed to arrange, in such a control device, controlled, or driven, locking mechanical means which block the actuation of the electrical switch with tactile effect and which, when they are electrically powered in response to a signal, unlock the actuation of this electrical switch with tactile effect.
These locking means consist of locking fingers belonging to electromagnets which, when the electromagnets are not powered, constitute fixed abutments which oppose the actuation travel of the force transmission member arranged vertically between the top panel and a push button, or the triggering member, of the electrical switch with tactile effect.
When, in response to a particular action of the user on the control panel, the locking electromagnets are powered, the latter release the abutment fingers and the user can then continue his or her vertical control action on the top panel to then provoke the change of state of the electrical switch with tactile effect which generates an electrical validation signal, and perceive in return the tactile sensation of this validation command.
Making use of mechanical locking means consisting of mechanical blocking abutments for which the unlocking is controlled by electromagnets is not satisfactory, notably for various reasons. For example, if a significant vertical force is applied by the user on the top panel, if unlocking does not occur, damage may occur to the locking means in their locked state.
Furthermore, the changes of state, between their locked position and their unlocked position, of the mechanical locking means are generators of unacceptable noises, notably through their amplification by the other components of the control device, and more particularly when such a control device is fitted for example in a motor vehicle passenger compartment.
Moreover, when the electrical switch with tactile effect has been actuated, after the controlled unlocking of the locking means, it is not possible to accurately determine the relative travels of the different components and it is not possible to determine whether, when the electrical power supply for the electromagnets is once again interrupted, the transmission member (whose control travel must be once again blocked) occupies a sufficiently high position to enable the locking or blocking state to be re-established.
The aim of the present disclosure is to provide a solution to these problems and to remedy the drawbacks which have just been mentioned.